The invention relates to an agent and a procedure for the detection of chemical substances and physical properties.
U.S. Pat. No. 5,607,834 discloses the use of a primer having a hairpin loop for the detection of a nucleotide sequence. In this procedure, a first and a second fluorophoric molecule are provided on the opposite loop sections of the hairpin loop. The fluorophoric molecules are designed here such that the fluorescence is extinguished by the radiation-free energy transfer. If the primer, however, is hybridized with a complementary opposite strand, the hairpin loop is opened. The spatial relationship between the first and the second fluorophoric molecule, which extinguishes fluorescence, is altered. Fluorescence is thus observable.xe2x80x94This procedure is only suitable for the detection of nucleotide sequences.
David J. Holme and Hazel Peck: Analytical biochemistry, Longnamm [sic], London and New York, 1983, pages 243-244 generally disclose the use of fluroimmonoassays [sic] for the detection of antigens.
It is the object of the present invention to specify an agent and a procedure which are universally suitable for the detection of chemical substances and physical properties.
According to the invention, an agent for the detection of chemical substances or physical properties is provided, having
a first polynucleotide or peptide sequence having a first fluorophoric group, whose first end is bonded to a solid phase and
a second polynucleotide or peptide sequence having a second fluorophoric group, whose second end has a group which is bondable or addable to the chemical substance to be detected or a group which is sensitive to the physical substance to be detected,
the first polynucleotide or peptide sequence being addable to the second polynucleotide or peptide sequence such that a spatial relationship making possible an interaction between the first and the second fluorophoric molecule is producible,
and during addition of the chemical substance to the group and/or action of an external force on the group the spatial relationship being terminatable and thus a fluorescence reaction is producible.
The agent is universally suitable for the detection of chemical substances and physical properties. For investigating the question of whether a certain chemical substance is contained in a solution, the agent is brought into contact with the solution. If the chemical substance is contained in the solution, it adds to the group. By the action of an external force directed away from the solid phase, e.g. of a centrifugal force, the spatial relationship between the first and the second fluorophoric group is altered. A fluorescence reaction is observable. This can be the extinguishing of a fluorescence formed in the presence of the spatial relationship. The fluorescence reactions are essentially based here on the so-called Fxc3x6rster effect.
To achieve the object, a procedure for the detection of chemical substances or physical properties is additionally provided, having
a first polynucleotide or peptide sequence having a first fluorophoric group, whose first end is bonded to a solid phase and
a second polynucleotide or peptide sequence having a second fluorophoric group, whose second end has a group which is bondable or addable to the chemical substance to be detected or a group which is sensitive to the physical property to be detected,
the first polynucleotide or peptide sequence being addable to the second polynucleotide or peptide sequence such that a spatial relationship making possible an interaction between the first and the second fluorophoric molecule is formed,
and during addition of the chemical substance to the group and/or action of an external force on the group the spatial relationship being terminated and thus a fluorescence reaction being produced.
The procedure is universally suitable for the detection of chemical substances and physical properties, such as, for example, the presence of a magnetic field. For this, for example, a magnetic chemical substance can be coupled to the group or a magnetic group can be provided. On applying a magnetic field which pulls the chemical substance or group away from the solid phase, the spatial relationship between the first and the second fluorophoric molecule is terminated. A fluorescence reaction is observable which indicates the presence of a magnetic field. The procedure according to the invention is moreover more rapid than conventional procedures for the detection of chemical substances, such as the ELISA procedure, because time-consuming conversion of a color-imparting substance is not necessary for the detection and because the washing steps for the removal of unbound antibodies are unnecessary.
According to one embodiment, the first and the second polynucleotide or peptide sequence are linked to give a molecule. In this case, the spatial relationship can be designed in the form of a secondary structure, in particular as a hairpin loop, helix or pleated sheet structure. Advantageously, the first fluorophoric molecule is bonded to a first loop section and the second fluorophoric molecule is bonded oppositely to a second loop section of the hairpin loop at a distance making possible an interaction.
The solid phase can be a, preferably electrically conductive, plastic. This expediently contains a polycarbonate, trimethylthiophene, thiophene, triaminobenzene and/or a polycarbene.
The polynucleotide sequence can be a deoxyribinucleic acid [sic] (DNA), a phospothionate nucleic acid [sic] (PTO) or a peptide nucleic acid (PNA). Instead of this, however, a peptide or a protein can also be used. The fluorescence reaction can be the production or the extinguishing of fluorescence.